Philips P2000M Troubleshooting Guide
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Philips's Field Service Manual has a fault isolation procedure written for the Philips P2000M, which starts at the monitor cabinet, works through the basic cabinet and screen, and ends with the supply checks at the board sockets. The maintenance program cartridge then tests the memory, keyboard, screen, interfaces and floppy drives.[1][2][3] The basic cabinet is the P2000T's; its supply and memory tests are explained in more detail on Philips P2000T Troubleshooting Guide. Safety and the monitor adjustments are on Philips P2000M General Maintenance.
Warning: the monitor cabinet contains mains wiring and the CRT's high voltage. Discharge the CRT before handling the monitor assembly (CRT Discharge Procedure).[4]
Philips's fault isolation procedure
[edit | edit source]| Step | Reaction | Action |
|---|---|---|
| 1. Switch on the monitor unit | Monitor power indicator lit | Wait 30 seconds; go to step 2 |
| No power-on indication | Check the mains connection (figure 1.9, callout 1), the fuses (callout 2), the power supply wiring and the indicator lamp; replace the monitor cabinet power supply | |
| 2. Remove cartridges and cassette; switch on the basic cabinet | Keyboard power indicator lit | Go to step 4 |
| No power indication | Check the mains connection; go to step 3 | |
| 3. Press the reset button | Beep | Check the keyboard connection; replace the keyboard (Philips notes "LED defective") |
| No beep | Check the fuses (figure 1.8, callout 1) and connections (callout 3); check the power supply at step 7 | |
| 4. Press the reset button | Screen shows "Philips/P2000 Microcomputer" | Go to step 5 |
| No screen, beep | Turn the brightness control fully clockwise; check the monitor interface connection and the monitor fuse (figure 1.9, callout 4); replace the video board; try the screen adjustments; replace the monitor assembly; replace the monitor cabinet power supply | |
| No screen, no beep | Check the basic cabinet wiring; replace boards; check the power supply at step 7 | |
| 5. Insert the maintenance program in the first slot and press reset | "Test Menue" | Run the maintenance program |
| "Philips/P2000 Microcomputer" | Go to step 6 | |
| 6. Switch off, wait 10 seconds, switch on | "Test Menue" | Check the reset button wiring; replace the reset button; replace the CPU board |
| "Philips/P2000 Microcomputer" | Clean the cartridge socket; replace the CPU board; replace the maintenance cartridge |
Supply checks
[edit | edit source]Basic cabinet
[edit | edit source]Steps 7 and 8 check the basic cabinet supply with the power cables unplugged from the CPU, video and extension boards.[2]
| Check | Where | If it fails |
|---|---|---|
| +5 V | Right-hand pin to second pin from the left of the CPU, video and extension board sockets | No 5 V anywhere: replace the power supply. CPU socket only: the top regulator. Video socket only: the second from the top. Extension socket only: the second from the bottom. |
| +12 V | Left-hand pin to second pin from the left of the CPU board socket | Replace the bottom regulator |
On the P2000M the second 7805 feeds the video board, so a video board that has lost +5 V shows as no screen with a beep at step 4.[5][1] TS1 and TS2 short the +12 V line while +5 V is missing, so a dead +5 V supply also takes +12 V away.[6]
Monitor cabinet
[edit | edit source]Philips gives no voltage check for the monitor cabinet beyond its power indicator. The schematic shows what each output should be.[1][7]
| Output | Regulator | Connector | Notes |
|---|---|---|---|
| +5 V, floppy drives and power LED | IC2, 7805, from the BY164 bridge D1 and C13 | CD3 and CD4, pin 5; LED on CD2 through R5 (270 Ω) | F2 (2 A T) on the transformer winding |
| +12 V, floppy drives | IC1 (723) with series transistor TS1 (BD645) and current-sense resistor R1 (0.15 Ω) | CD3 and CD4, pin 1 | Adjustable with R4 (5 kΩ); sensed through R2, R3 and R4. Fed from the 1N5401 bridge D2 to D5 and C14 to C16, F1 (2 A T) |
| +12 V, monitor | IC3, 7812 | CD5, pin 1 (ground on pin 2) | Same rectifier as the floppy +12 V |
The Field Support manual's text calls the +5 V regulator IC1. On the schematic the 7805 is IC2 and IC1 is the 723 for the floppy +12 V; the table follows the schematic.[6][7]
The monitor fuse (1.25 A in the Field Service Manual) is a separate fuse for the monitor assembly, callout 4 in figure 1.9.[8][1]
Floppy drive faults
[edit | edit source]| Test | Reaction | Action if not correct |
|---|---|---|
| 7.1 Read master disk | Tracks 0 to 34 of a master disk are read | Check the interface; try drive 2 if fitted; replace the master disk; replace the drive; replace the extension board |
| 7.2 Write/read test disk | Writes, reads and steps all tracks | Clean the head; replace the disk; replace the drive; replace the extension board |
| 7.3 Continuous read of one track | Steps to the requested track | Enter the data the program asks for |
The floppy controller is on the extension board in the basic cabinet, not in the monitor cabinet.[9] Check the drive straps and terminator before condemning a drive; they are listed on Philips P2000M General Maintenance.[10]
Screen faults
[edit | edit source]- No picture with a beep: work through step 4 above, starting with the brightness control.[1]
- Rolling, wrong size, poor focus or linearity: the eight monitor adjustments are on Philips P2000M General Maintenance.[11]
- Wrong or missing characters: the maintenance program's character and graphics tests point to the character generator, which on the P2000M is on the video board.[3][9]
Related pages
[edit | edit source]- Philips P2000M
- Philips P2000M General Maintenance
- Philips P2000M Capacitor Replacement Guide
- Philips P2000T Troubleshooting Guide, for the basic cabinet
- Philips P2000 Documentation
References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Philips Data Systems, Field Service Manual P2000, publication 5122 991 30703, October 1982, pp. 1-22 and 1-23: figure 1.9 (monitor cabinet) and section 1.2.4.2, M-version procedure steps 1 to 4. Hosted as File:Philips P2000 Field Service Manual 5122 991 30703.pdf.
- ↑ 2.0 2.1 2.2 2.3 Philips Data Systems, Field Service Manual P2000, October 1982, p. 1-24: M-version steps 5 to 8, including the 5 V and 12 V checks at the board sockets and the regulator to replace for each. Hosted as File:Philips P2000 Field Service Manual 5122 991 30703.pdf.
- ↑ 3.0 3.1 3.2 Philips Data Systems, Field Service Manual P2000, October 1982, pp. 1-25 to 1-29, section 1.2.4.3: maintenance program, including the screen tests and the floppy drive tests 7.1 to 7.3. Hosted as File:Philips P2000 Field Service Manual 5122 991 30703.pdf.
- ↑ Philips Data Systems, Field Service Manual P2000, October 1982, p. 1-19, section 1.2.3: safety procedures, including discharging the CRT. Hosted as File:Philips P2000 Field Service Manual 5122 991 30703.pdf.
- ↑ Philips, Documentatie P 2000 (Field Support manual, 8111), p. 4-33, figure 4.14: power supply basic cabinet, regulator 2 to the video board (CD3). Hosted as File:Philips P2000 Field Support Manual 8111.pdf.
- ↑ 6.0 6.1 6.2 Philips, Documentatie P 2000 (Field Support manual, 8111), p. 3-23, sections 3.4.1 and 3.4.2: the basic cabinet supply and its TS1/TS2 protection; the monitor cabinet supply (the text names IC1 as the +5 V regulator for the floppy drives and power LED, the D2 to D5 bridge with C14 to C16, IC3 for +12 V to the monitor, the floppy +12 V from IC1 and TS1, adjustable with R4). Hosted as File:Philips P2000 Field Support Manual 8111.pdf.
- ↑ 7.0 7.1 7.2 Philips, Documentatie P 2000 (Field Support manual, 8111), p. 4-35, figure 4.16: power supply monitor cabinet, drawing 5103 108 5035 dated 27.8.80. Hosted as File:Philips P2000 Field Support Manual 8111.pdf.
- ↑ Philips Data Systems, Field Service Manual P2000, October 1982, p. 1-14: monitor cabinet fuses, 1.25 A monitor assembly, 2 A (T), 4 A (T). Hosted as File:Philips P2000 Field Service Manual 5122 991 30703.pdf.
- ↑ 9.0 9.1 Philips Data Systems, Field Service Manual P2000, October 1982, pp. 1-30 to 1-33, sections 1.2.5.1 (extension board, with the floppy controller µPD765) and 1.2.5.2 (video board, with the character generator). Hosted as File:Philips P2000 Field Service Manual 5122 991 30703.pdf.
- ↑ Philips Data Systems, Field Service Manual P2000, October 1982, p. 1-41, section 1.2.6.2: floppy drive straps. Hosted as File:Philips P2000 Field Service Manual 5122 991 30703.pdf.
- ↑ Philips Data Systems, Field Service Manual P2000, October 1982, pp. 1-42 and 1-43, section 1.2.7.2: monitor adjustments. Hosted as File:Philips P2000 Field Service Manual 5122 991 30703.pdf.